better ways to calculate the cartesian path for move_group
Hi all,
I wonder if there are better ways to calculate the cartesian path other than the computeCartesianPath() of move_group.
Instead of letting move_group pass random samples of target pose within tolerance to the ik solver, now I call the ik solver directly, which can increase the efficiency of finding solutions.
I think computeCartesianPath() does the same trick, i.e. passing random samples of target pose to ik solver, right? But it seems this function also does other things like calculating the velocity, finally generating a trajectory (type moveit_msgs::RobotTrajectory). Therefore if I call the ik solver directly here, I also need to calculate the velocity and enclose them as moveit_msgs::RobotTrajector, seems a lot of work..
trac_ik seems to have a cartesian path planner, but I can't find the source code of this part in https://bitbucket.org/traclabs/trac_i...
Could you point to where you believe this is happening? IIUC,
computeCartesianPath(..)uses linear interpolation with slerp between two poses with a given step-size.I'm not aware of it doing anything "random".
Sorry, I didn't state it very clearly. I mean when moveit tries to get the ik solution of these interpolation points, it passes these points plus a random noise within tolerance, rather than pass the exact interpolation points to the iksolver. Like I posted here.
It would still be good if you could link to the code.
one possible place in the code is here. line 414-506. Not sure if other place also does that.
That would be moveit_core/constraint_samplers/src/default_constraint_samplers.cpp; L414 to L506 in
ros-planning/moveit.Please try to always link to the Github repository.
As far as I can tell, constraint samplers are not used in
computeCartesianPath(..). Could you point to the lines incomputeCartesianPath(..)which you believe are using the constraint sampler? Or any other place where it adds randomness?quote: "As far as I can tell, constraint samplers are not used in computeCartesianPath(..)."
Then I might be wrong, sorry for that. I thought
computeCartesianPath(..)also uses it to solve ik of interpolation points.I'm not claiming you're wrong immediately. Afaict, in the end
setFromIK(..)is used (here), which ends up here. This can be passed a constraint callback I believe (in theconstraintargument), but I'm not sure whether that ends up in/with the file you link to.Perhaps @v4hn can add something here.